Should the Changan Yidong Plus use 92 or 95 octane gasoline?
1 Answers
According to the official vehicle manual recommendation, the Changan Yidong Plus should use 92 octane gasoline. In addition to checking the appropriate gasoline grade in the vehicle manual for the Changan Yidong Plus, you can also find it on the fuel tank cap, which will also be marked. Usually, the gasoline grade can also be determined based on the engine's compression ratio. Vehicles with an engine compression ratio between 8.6-9.9 should choose 92 octane gasoline, while those with a compression ratio between 10.0-11.5 should opt for 95 octane gasoline. However, with the use of some new technologies nowadays, the gasoline grade cannot be solely determined by the compression ratio. A high compression ratio can also be tuned to use lower-grade gasoline. This is because, apart from the compression ratio, other factors such as ignition timing, turbocharging technology, and Atkinson cycle technology also play a role. Generally, the higher the gasoline grade, the higher the octane number and the better the anti-knock performance. 92 octane gasoline contains 92% isooctane and 8% n-heptane, while 95 octane gasoline contains 95% isooctane and 5% n-heptane. If the Changan Yidong Plus occasionally uses the wrong gasoline grade, simply switch back to the correct grade after consumption. However, long-term use of the wrong gasoline grade can have the following effects: For vehicles recommended to use lower-grade gasoline, mistakenly using higher-grade gasoline will not cause damage, but the increase in octane number will change the fuel's ignition point, leading to delayed combustion in the engine. This means both the engine's power output and thermal efficiency will decrease, resulting in poorer performance as experienced in real feedback. For vehicles recommended to use higher-grade gasoline, using lower-grade gasoline can cause engine knocking. Because the octane number is too low, the gasoline's ignition point decreases and may ignite prematurely during the compression stroke. If combustion occurs before the spark plug ignites during the compression stroke, resistance will arise during the upward stroke. This resistance makes the engine run very unstably. If it's mild knocking, it only increases noise without significant damage to the engine. However, if there is noticeable knocking, it indicates severe engine conditions. The vibration not only affects driving stability but also causes abnormal wear on the pistons and cylinders, and in severe cases, can lead to cylinder scoring.
